Bernie Masters is a geologist/zoologist who spent 8 years as a member of the Western Australian Parliament. Married to Carolina since 1976 and living in south west WA, Bernie is involved in many community groups. This blog offers insights into politics, the environment and other issues that annoy or interest him. For something completely different, visit www.fiatechnology.com.au for information about vegetated floating islands - the natural way to improve water quality.

Wednesday, March 04, 2015

Melatonin and Aspirin - two common, cheap drugs that together prevent cancer and protect the cardiovascular system

Melatonin, the new partner
to aspirin?

Aspirin is the most common drug taken for cardioprotection,
with the added benefit of anticancer properties. Yet, it causes gastric haemorrhage.
An alternative, safer cardioprotective drug than aspirin is needed.

Melatonin, commonly taken to induce sleep or counter jet
lag, has cerebroprotective and anticancer properties, with no reported side-effects.
We hypothesise that melatonin has beneficial preventive properties for various
organ diseases through mechanisms not shared by aspirin.

Melatonin is synthesised mainly in the pineal gland. Its
secretion into the bloodstream is regulated by the environmental light–dark
cycle via the suprachiasmatic nucleus. The initial event is that very sensitive
ocular photoreceptors stimulate formation of melanopsin within the basal
retinal ganglia, which, in turn, sends signals to the pineal gland, from which
release of melatonin, synthesised from serotonin, is either stimulated or
inhibited.

Melatonin acts by both inducing sleep and restoring the
inherent sleep rhythm that is related to the rise and fall of blood melatonin
concentrations. Melatonin treatment helps to restore these human circadian
rhythms, resulting in better cognition and less daytime fatigue1.
Experimental and clinical data have implicated melatonin in reduction of
ischaemic-reperfusion injury, as originally studied in isolated rodent hearts2.
If melatonin concentrations also affect the occurrence of human infarcts, then
the day–night pattern of changes in melatonin blood concentrations2
becomes relevant. In patients with ST-elevation myocardial infarction, the
normal pattern is reversed, with less melatonin produced at night3.

In the brain, melatonin inhibits the potentially lethal opening
of the mitochondrial permeability transition pore in isolated brain
mitochondria, albeit at high concentrations4.

Finally, melatonin has antidiabetic5 and not well
studied anticancer properties.

Overall, the organ and vascular protective qualities of
melatonin at the cost of very few or no side-effects far exceed those of
aspirin, which is much more widely used for cardioprotection than melatonin is.
We declare no competing interests.